


Nightfell

by CubicCrystal



Category: Steven Universe (Cartoon), Undertale (Video Game)
Genre: Angst, Crossover, Everyone has gone mad, Flowey is a pure sweetheart, Gen, Horror, More tags will be added as the story progresses, Nightfell AU, Plot, Undertale Neutral Route, i promise there will be some romantic amedot later, well not too much horror but the horror tag seems appropriate for this
Language: English
Status: In-Progress
Published: 2016-11-26
Updated: 2016-11-26
Packaged: 2018-09-02 09:59:34
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,192
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8663047
Author URL: https://archiveofourown.org/users/CubicCrystal/pseuds/CubicCrystal
Summary: Amethyst and Peridot have fallen into a cavern. Confused and hurt, they traverse the Underground, searching for a way to leave before night falls: when the monsters fall into mania.





	

_ wake up _

A small, soft voice called out from the void.

_ wake up... _

It tried to become louder...

_ wake up..! _

... but it couldn't.

_ wake up wake up wake up wake up... _

Its efforts were in vain.

_ you... you have to stay determined, remember... _

_ remember..? _

 

Peridot's eyes fluttered open. Several realizations struck her like lightning bolts, all at once: first, her back was absolutely  _ killing  _ her; second, she was in a dark room, like a cave-

She was in a cave. Why was she in a cave?! She searched for a memory, but all she could remember was the day before. She was in the barn, playing Scrabble with Steven and Lapis while the others were on a mission. Pearl had warped back alone… she looked worried… but after that, there was only a blur, passing too quickly to understand.

She sat up, causing a painful shock to soar up her spine that made her yelp in surprise. Someone else must have heard her, as she almost immediately could hear quiet, uneven footsteps growing louder as they got closer.

Peridot could see a shadowy figure, becoming clearer as it limped closer. Soon, she recognised the figure as Amethyst.

“You fell too?” the purple Gem asked between coughs.

“I…” Peridot looked up at the hole above her, covered in a bright film that must’ve been made of magic. “I suppose so.”

Amethyst extended her hand. “Here. We need to get moving. I dunno what’s down here, but I heard growling coming from down that way.” She pointed behind herself.

Amethyst helped Peridot get off of the ground, which Peridot noted was covered in small, delicate golden flowers. Amethyst threw Peridot’s arm over her own shoulder, and together, they slowly and cautiously walked down the corridor.

After what felt like an eternity, they turned a corner and saw a single golden flower beneath a lightbeam. As they got closer, noticed that the flower had a face and two glowing, floating leaves. The Gems slowed to a stop, and all they could hear was soft crying.

The flower looked up at them; tears streaming down his face. “H-howdy…” he sniffled. “I’m Flowey.”

“Are you okay?” Peridot asked.

“I don’t think anybody is anymore. This place has known only misery for years. You don’t want to be down here… you really, really don’t…” Flowey trailed off into more tears.

“What happened?” Amethyst asked. “Something must’ve happened.”

“Nightfell.” Flowey shivered.

“Night fell? Doesn’t that happen every evening?” Peridot questioned.

“No… it’s a horrible condition, caused by extremely intense emotion. In the day, nightfells are keen, intelligent, and spiteful beyond anything you’ve ever seen. At night, they slip into horrible mania. Beyond that, I don’t know. I’m the only one left who doesn’t have it.” Flowey sighed. “But that leaves me as the only one left who can grieve…”

“Is there a way to fix it?”

“I don’t know! I’ve tried for years and years, but nothing has worked. I can’t… I couldn’t… I...” Flowey trailed off again.

“We’re here, and since we might not get out of here for a while anyway… we’ll do the best we can to help,” Amethyst offered.

Flowey stared at the Gems for several seconds. A tiny smile formed on his face, and he shook the tears off of his face. “Thank you.” His expression became more serious. “Toriel will be here soon. If she sees you, you might not get out of here before night, and you  _ really _ don’t want to be around a nightfell at night. I know a good hiding spot where we can wait until she leaves.”

The Gems nodded, and Flowey popped into the ground. A few seconds later, he called out again. “Follow my voice. Follow my voice. Follow my voice,” he repeated as the two Gems maneuvered through the darkness. Soon, all three were hiding silently behind a fallen pillar.

It didn’t take long until soft footsteps echoed through the cavern, accompanied by rough, sinister humming. The first sight of Toriel that they saw was a wide, evil grin accented by razor-sharp, jagged teeth and glowing red eyes. As she stepped into the lightbeam, the rest of her terrifying form became clear. Her dark violet robe was tattered and torn, exposing matted fur underneath. Her arms were large and muscular, and long claws extended from her paws below. When she took a step forward, her robes moved up just enough for the trio to see oversized cloven hooves in place of the other set of paws they had expected.

If the Gems hadn’t known she was a “normal” monster beforehand, they would have assumed she was a demon.

Flowey gave the Gems a small, slow nod, as if to say “That’s her.”

Toriel meandered into the room the Gems fell in, and Flowey nudged Amethyst’s arm with a magical floating leaf. “We need to go now. She’ll be back in here in about five minutes.

… Do you mind if I ride on your arm?”

-=]|[=-    -=]|[=-   -=]|[=-

The trio marched on through the Ruins. Flowey was curled snugly around Amethyst’s right arm, and around the other was Peridot’s own arm.

They went through several rooms, each with a new puzzle. Flowey solved most of them, but occasionally Peridot would trot forward and solve one on her own, to which Amethyst would affectionately mutter “nerd”.

“Most of the puzzles that used to work don’t anymore,” Flowey explained. “Toriel used to keep them well tended to, but since she became nightfallen, she’s been more focused on personally capturing those who fall into the Underground. Luckily, this makes it easier for us to pass through here.”

“So… nightfells only focus on one thing?” Peridot observed.

“They have to. If they focus on too much, they can’t hold their body together, and the instability of their soul causes their body to melt. Many monsters learned this the hard way…”

The trio walked along in silence, which was soon interrupted.

_ Ribbit. _

Their eyes followed where the sound was coming from.

_ Riiibbit. _

There stood a small frog-looking creature with six legs and deep, dark, evil eyes.

_ Riiiiii-aaaAAAAAA _

Its mouth expanded into a massive, toothy hole that could’ve easily swallowed someone whole, if only the little monster’s body was big enough to hold it. Peridot jumped behind Amethyst in shock.

_ AAAAAAAAAAaaaaaa _

The deafening screech became a high-pitched buzzing noise, which soon faded into white noise.

Amethyst and Peridot’s gems began to glow, and glowing flies popped into existence and darted towards the confused Gems.

“You’re in battle! Dodge the flies and talk to the frog,” Flowey called out.

“Talk to it?!” Amethyst snapped as she jumped out of the way of a swarm of insects.

“Yes! Just… just hurry up and do it!”

“I’ll do it. Hey, frog!” Peridot began. “You… um… have nice eyes??”

The monster’s mouth got slightly smaller.

_ hhhhhhh. _

Another group of flies swarmed the Gems.

Amethyst thought for a moment. “Uhh… your mouth is the biggest I’ve ever seen..?”

_ hhh… _

The white noise was barely audible anymore.

“Y-you have six legs instead of four and I think that’s pretty cool!” Peridot yelled out.

Suddenly, the frog’s mouth closed. It began to glow so brightly that the trio had a hard time looking at it directly.

An upside-down white heart emerged from the light and floated towards the Gems. It looked like a stereotypical video game glitch: dark buzzing squares rippling across its surface, bits and pieces of the heart occasionally teleporting off and on.

“That… that’s its soul…” Flowey said in awe.

Peridot meekly reached out to try to bubble the soul, but before Flowey could warn her otherwise, the soul became a small white stone and fell into her hand.

The frog disappeared, and in its place was a floating light-blue star.

The trio was filled with patience.

-=]|[=-   -=]|[=-   -=]|[=-

The rest of the journey through the Ruins was quite simple. They fought a few monsters here and there, each one turning into a blue star and soul-stone. Most of the puzzles were either already solved by Toriel, or simply out of order, and the rest were easily solved.

Eventually, they came across a small house. As they got closer, it was apparent that the resident didn’t care about the house too much. Its windows were shattered, and the door was only attached to the wall by its top hinge. A music box played from within; it sounded broken and distorted. Everything about this house screamed “abandoned”, but somehow the Gems knew it wasn’t.

“This is Toriel’s house,” Flowey informed.

Amethyst whistled. “Dang, are we sure she  _ actually _ still lives here?”

“I saw her baking a pie in here four days ago, so my guess? Yeah, she lives here.”

“It looks like she has some crazy grudge against this house.”

“That actually sounds somewhat accurate.”

“Wow.” Amethyst decided to step into the house, with Peridot clinging to her arm like a frightened child.

The interior of the house was even more of a disaster than the outside. Flowerpots had been knocked over and shattered, walls and furniture had been clawed at, and many floorboards were sticking up.

“We need to move before Toriel gets back. No doubt she’s almost here,” Flowey warned.

“Where do we go?” Amethyst asked.

Peridot pointed at the stairs in front of them. “Maybe down those stairs?”

Flowey nodded. “That’s probably a safe bet.”

The Gems hobbled over to the stairs, and carefully stepped down into a dark corridor. They walked as fast as they could to the end of the hallway, only to be greeted by another after turning to the left. At the end, they found a door. Amethyst tried to open it, but it wouldn’t budge.

“Flowey, how do we open this door?”

“Do you really think I know? I don’t use doors!”

“How do you get around, then?”

“I just pop into the ground, and pop back up wherever I need to.”

“Okay, but we really need to get out of here!” Peridot interjected.

Amethyst rattled the handle. “I can’t-”  _ rattle  _ “-get this stupid-”  _ rattle _ “-door open!”

Footsteps echoed through the corridor. Peridot almost shrieked, but Flowey placed a magical leaf over her mouth.

A surprisingly soothing voice called. “Hello? Are you ther e, children?”

The Gems turned around to see Toriel standing right behind them.

“I am Toriel, caretaker of the Ruins.”

Her voice became more demonic as she grinned evilly. “ _ And I’ll take GOOD care of you.” _

A feeling of vertigo washed over the Gems. Their ears rang as Toriel laughed sweetly yet maniacally.

“I’ve missed having children around here,” she sighed. “Too bad none of them lasted more than a day.”

A storm of fireballs flew at the Gems, but were skillfully dodged.

“Toriel, we don’t want to fight!” Peridot yelled.

“Ah, how kind. Now it’ll be easier to  _ end _ you.”

Peridot squeaked as Amethyst pulled her away from an incoming fireball.

“We just want to go home!”

“This  _ is _ your home, idiot!” she howled.

Amethyst summoned her whip. “ _ What did you just call her?” _

Peridot nudged her. “Amethyst, no. You don’t have to fight just because she insulted me.”

“Eh, I was about ready to start fighting anyway.”

Toriel looked down at the Gems with a haughty glare which reminded Peridot of Yellow Diamond. She hid even farther behind Amethyst.

Amethyst’s expression went from simple anger to pure rage, and she threw her whip at Toriel. It hit her in the arm, and quickly dissipated.

“You would dare hit your mother?!” Toriel hurled more fireballs.

“You’re not my mother!” Amethyst spat as she threw another whip, which managed to wrap around Toriel’s legs.

Toriel growled a deep, demonic growl as she threw a series of unavoidable walls of fireballs at the frightened Gems. As each layer hit them, she called out at them.

“You worthless idiots!”

They felt their souls depleting.

“I’ve been wasting my time!”

They lost patience.

“I should have killed you when I first had the chance!”

Somehow they knew that if they died in this way…

“ _ I’ll just have to kill you now!!” _

… there would be no coming back.

They were ready to give up. There was no winning… there was no way… no way to…

“ _ No!”  _ Flowey shrieked. A wall of magical leaves formed in front of the helpless Gems. “I never wanted this. I never wanted you to die... I…

…

I guess I have to do this, don’t I?”

Thorny brambles shot up from the ground around Toriel. A look of horror spread across her face as they closed in on her. She cried out as she melted into a pile of white dust, leaving her soul floating where she had once stood. 

Flowey slithered off of Amethyst’s arm. He popped into the ground, popping back up at the mound of dust. He extended two magical leaves to the floating heart, which turned into a clear crystal.

As he held the soul crystal, Flowey began to cry. “I’ll keep you safe.” The crystal disappeared in a shimmer of light, and one of Flowey’s petals glowed as he absorbed the soul. He popped over to the door, and Toriel’s soul opened it.

Flowey sighed. “Let’s go.”

**Author's Note:**

> I know, I know, "why did you skip out writing the travel through the Ruins?" There wasn't too much I could write about there, as the trio would've been fighting the same types of monster over and over for 75% of the time, and the rest would be silent walking. Also, Napstablook isn't in the Ruins right now. You'll see him later, I promise.


End file.
